Currently, agricultural harvesting machines such as combines typically include a chopper which can be used for chopping and/or propelling crop residue onto a harvested field, which will typically include stalks, leaves and cobs separated from corn or maize; straw and chaff separated from wheat and other grasses; and stalks, leaves and pods of legumes such as soybeans. In many instances it is desirable for the crop residue to be spread as evenly as possible over the width of the harvested swath, to avoid problems resulting from uneven spreading, such as, but not limited to, difficulty in passage of fall tillage tools through residue clumps or thick areas; uneven insulation of the field resulting in uneven field warming and thawing and weed or crop emergence during the following planting season; and increased rodent and insect habitat.
Known choppers typically include a plurality of rotary knives or flails which propel the crop residue within a housing of the chopper and against fixed knives or bars, so as to be chopped thereby, and outwardly through a discharge outlet of the housing optionally, the fixed knives or bars can be removed or retracted, such that the crop residue is propelled directly outwardly through the discharge outlet, without being chopped, which is desirable, for instance, when harvesting corn or maize. The term chopper as used herein refers to devices both with, and without, fixed knives or bars. It is known to provide a residue spreader or distributor for guiding airborne flight of the crop residue from the chopper for distribution over a field, for instance, in a pattern having an adjustable sideward extent or width, which can be, for instance, adjusted to have a width about equal to the width of a header and thus a harvested swath of a field. Reference in this regard, Baumgarten et al. U.S. Pat. No. 5,569,081; and Bischoff U.S. Pat. No. 6,331,142.
Combine headers having a width of 30 feet are currently well known, and headers having widths of 36 feet are also known. As noted above, in many instances it is desirable to uniformly or evenly cover a harvested field. Thus, for optimum performance, the sideward distance that a spreader should be capable of guiding crop residue is important, as is the uniformity or pattern of the spread. Further, the accuracy of the placement of the crop residue in relation to a harvested swath is important, as it is generally not desirable to distribute the crop residue in a manner so as to leave uncovered strips or areas of the swath, double covered areas, or to spread the residue in an adjacent area of unharvested crops so as to be possibly inducted into and processed by the machine. It has been found, however, that such uniform coverage can be difficult to achieve when conditions vary, which conditions can include winds, particularly cross winds; the contours of a field or obstacles therein require following curved swaths; and when turning is required, such as in the headlands of a field. Typically, when cross wind conditions are present, the sideward alignment of a pattern of crop residue deposition will have to be adjusted when harvesting machine changes direction. Reference in this regard, U.S. Pat. No. 5,569,081, which attempts to overcome this problem using a complex, multiple linkage arrangement involving servomotor controls for controlling the positions of guiding plates or vanes of the spreader for making adjustments to compensate for wind. Automatic directional control is also addressed in Bueermann U.S. Pat. No. 6,729,953, which also uses a complex linkage arrangement for this purpose.
An observed disadvantage of such known spreader apparatus is that sideward adjustment of the locations of the edges of a pattern of crop residue deposited on a field, for instance, for aligning with edges of a swath of harvested crops, is made by adjusting the sideward extent or width of the pattern. This is typically done by changing an angle or upward and downward tilt of the spreader apparatus about a horizontal axis, and/or by moving the guiding plates or vanes sidewardly. In this latter regard, the known apparatus rely on relatively complex adjustment mechanisms for the guiding plates or vanes, in addition to other mechanisms or apparatus for supporting the spreader itself, such as hinges, locking devices, and the like, for upward and downward movement. Some of such mechanisms have been found to have less than desirable durability and require more frequent than desirable adjustment. Operationally, other possible shortcomings of using such complex linkage arrangements include that end play and manufacturing tolerances may make precise adjustments more difficult and time consuming. And, altering the sideward position or orientation of vanes may undesirably change one or more characteristics of the pattern of residue deposition, such as the uniformity or consistence of coverage, or the like.
Thus, what is sought is a spreader apparatus for a chopper which is quickly and precisely operable and adjustable for sidewardly positioning or aligning a pattern of crop residue deposition on a field responsive to, or, in anticipation of, conditions such changes in wind direction and/or velocity, and/or changes in direction of movement and the like, which is simpler than known constructions, including in terms of mounting, and which avoids one or more shortcomings and problems of the prior art devices.